Air hammer and the like



y Feb. 2L "19m,

F, H. BORM AIR HAMMER AND THE LIKE Filed July l2, 1935 2 Sheets-Sheet l Feb., 21, 939. F. H* BORM 2,147,685

` AIR HAMMER AND THE LIKE Filed July 12, 1935 2 sheets-shewv 2 Patented Feb. 21, 1939 UNITED STATES PATENT OFFICE 13 Claims.

This invention relates to improvements in air hammers and the like, and more particularly to improvements in hammer construction and in the die supporting means, the air hammer being particularly adaptable for body and fender work in "connection with automobiles as well as any other similar uses.

One of my objects is the provision of a simple, inexpensive and efficient air hammer construction.

Another object is to provide an air hammer having a more eicient striking surface.

Another object is to provide an air hammer having a more exact alignment of the ydie and the hammer surface. Another object is to provide an improved die supporting means.

Other objects and advantages will appear and be brought out more fully in the following specification, reference being had to the accompanying drawings, in which:

Fig. 1 is an elevation of a typical form of my air hammer;

Fig. 2 is a sectional elevation taken along the line 2-2 of Fig. 1;

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2, showing a removable hammer head cap;

Fig. 4 is a side View of the cap itself;

Fig. 5 is a partial view in sectional elevation of the hammer cylinder showing a modiiied arrangement for mounting a hammer cap;

Fig. 6 is a view similar to Fig. 5, showing a further modified method of mounting a hammer Call);

Fig. 7 is an elevation partly in section of the die supporting means;

Fig. 8 is a modified form of die supporting means;

Fig. 9 is a view similar to Fig. 1, showing a iurther modied die supporting means;

40 Fig. 10 is an end view taken on the line Ill-III of Fig. 9; and

Fig. 11 is an elevation partly in section showing -in detail the die holding means of Figs. 9 and 10.

The embodiment of my invention first chosen to illustrate the application of the general principles involved comprises a substantially rigid U- shaped frame I0, one end of which is mounted `in a sleeve II by screws or other similar means. The sleeve II has an integral, reduced, rounded, flattened portion I2, which portion in turn has a `bore I3 receiving a pivoted cap bolt I4, which bolt is also pivoted to a rounded, reduced, attened portion I5 of a die holder I6 having a spindie I'l. The spindle I'I hasan enlarged portion I8 and a reduced portion I9, and is provided with a shoulder 2U. The die holder I6 has a transverse bore 2| in which is located a guide and lock pin 22. A chambered cap 23 is provided, which has an aperture 24 adapted to receive the reduced portion I9 of spindle Il, and has an upper flat wall 25 and a pair of slots 26 adapted to receive the ends of guide pin 22 and to provide for relative movement therewith. Located within chambered cap 23 is a compression spring 21 which bears against the inner side of wall 25 and shoulder 2li. A die member 2B is shown` having a reduced bore 29 and a at base portion 30 adapted to seat on the upper wall 25 of cap 23, the bore 29 being adapted `to receive spindle I'I. I show a cross bore 32 in the die member 28, which bore is for convenience in turning or removing the die 28 as may be desired during the operation of the device. The die 28 has a die head 3| which in the embodiment shown is substantially flat. The die 28 is readily removable from the spindle, and other dies of different shapes substituted by rotating the die holder I 6 on pivoted cap bolt I4, this arrangement having been clearly disclosed and explained in my co-pending application, Serial No. 15,542, filed April 10, 1935, and need not be further explained in this application. The arrangement of the parts of the die and holder is such that a. space 33 is normally left in the reduced bore 29, which `space is of importance as will be more fully apparent hereinafter.

The other end of frame I5 is xed by conventional means such as screws to a sleeve casting 34, to which is integrally connected a hammer cylinder 35, and sleeve 34 has an aperture lug 36 adapted to receive and hold the end portion of an air hose 3l, which air hose is provided with a coupling 38 connected to a valve coupling 39 of a valve 40 which controls the inlet air under pressure to the interior of the hammer cylinder, to be more fully explained hereinafter. The hammer cylinder 35 is provided with an internal enlarged cylindrical bore 4I and a reduced internal cylindrical bore 42. The hammer cylinder is provided with a pair of downwardly projecting semicircular aprons 43, as will also be clear from reference to Fig. l0, and within the cylindrical bores 4l and 42 is located an air hammer 44 which is provided with an enlarged portion and a reduced portion 46, which enlarged and reduced portions respectively are adapted to have a close fit with the enlarged and reduced cylinder bores 4I and 42 and are slidable therein. 'I'he hammer 44 is provided with a central bore 4l, and in the position shown in Fig. 2, a lower chamber 48 is provided in the upper enlarged cylindrical bore 4|, and an upper chamber 49 is also provided in bore 4I. The hammer 44 is` provided with a lateral bore 50 which constitutes an intake port for the air, and a plurality of exhaust ports 5|. A plurality of auxiliary intake ports 52 are also provided in the hammer 44, the purpose and operation of which ports will be more fully explained hereinafter. The upper chamber 49 s closed and sealed by cap 53 which is held in place by screw threads or other suitable and equivalent means.

The downwardly projecting semi-circular aprons 43 are provided with a pair of semi-circular recesses 54 having stop shoulders 55, and a floating hammer head cap 56, Fig. 4 is provided, having a substantially flat work surface or ironing surface 51, and a hammer surface 58. The hammer cap 56 is provided with a pair of upstanding semi-circular flanges: 59 which are in turn provided with flange ring portions 60 and shoulders 6I, which flange rings are adapted to engage in the recesses 54 of the aprons 43, Fig. 2. A stop pin 62 is provided in one of the aprons 43 and extends into recess 54, and is adapted to engage the end portion of one vof the flange rings 60. A spring latch 63 is provided and is adapted to engage the other end of the flange ring 60. The hammer cap 56 is placed in the hammer head by inserting it upwardly at a ninety degree position from that shown in Fig. 3, the spring latch 63 withdrawn, and the cap and the flange rings 68 inserted in the recesses 54 by a ninety degree turning movement, and the latch 63 released for engagement with the end of the flange ring portion, as will be apparent to those skilled in the art.

I show in Fig. 5 a modified arrangement of the hammer head cap which is .designated by 64 and is provided with an upstanding cylindrical flange 65 provided with a pair of slots 66, in which and engaging which are a pair of threaded studs 61 which extend through and are secured to the aprons 43. It will be obvious from this View that the cap 64 is permitted to have vertical movement limited by the length of the slots 66.

In Fig. 6 I show another modification of this arrangement, in which the aprons 43 are provided with a pair of slots 68 in which is locate-d a pair of spring latch studs 69, which studs limit the movement of the hammer head cap 64 by the amount permitted by the slots 66.

When the device is in operation, the work is clamped firmly between the anvil head or die 3| and the hammer head cap 56, the spring 21 forcing the anvil or die upwardly against the undersideV of the work. The rougher the part of the work between these elements, the tighter it is clamped. With each blow of the hammer, the movable hammer head cap is driven downwardly with relation to the hammer cylinder 35 and tends to flatten the work. On the rebound, the spring 21 forces the die or anvil upwardly to compensate for the amount of flattening accomplished at each stroke. As the work nears completion the relative movement of the hammer head cap decreases, as is obvious. It is also obvious that as the work nears completion, and considering the appreciable amount of longitudinal movement permitted in the hammer head cap, the eiective blow of the hammer may be nicely controlled by the operator by merely raising or lowering the entire device with relation to the work and yet maintain the hammer head cap in constant contact with the work, as is desirable. This is essential in nicely nishing the work.

In Fig. 7 I show a modification of the die support, which consists of a modied form of chambered cap 10 having a spindle aperture 1I and an upper wall 12. At 13 I show a collar adapted to sli-de over the reduced portion I9 of spindle I1, and the collar has a pair of diametrically opposite apertures 14 in alignment with a radial spindle bore 15, which apertures and bore are adapted to receive a locking pin 16. It will be apparent from this gure that the pin 16 holds the collar 13 in position on spindle l1, and collar 13 limits the movement of cap 10 which is held against it by the pressure of spring 21.

In Fig. 8 I show a modification of the die support wherein the frame member I6 is continued upwardly, terminating in spindle portion 11, which spindle portion is provided with a bore 18 to receive the locking pin 22, the ends of which are located in slots 26 of the cap 23, and a washer 19 is located on the spindle 11 against pin 22, and a spring 21 is located between the upper wall 25 of the cap 23 and the washer 19.

Figs. 9, 10, and 1l show a further modification of the die holder and also show a section of the fender or similar piece A which is to be worked upon. A modified form of die holder 28a is provided with an enlarged cylindrical bore 2921, and in the position shown in Fig. 11 a space 33a is provided, a collar 89 being located on the spindle I1 and held thereby a forced t. The collar 80 performs the same function as collar 13 of Fig. '7.

It will be clear from the foregoing description that the die 28 when placed on the spindle I1 will seat on the flat wall portion 25 of the chambered cap 23, and in the normal position, as shown in Fig. 2, a substantial space 33 will be formed in the bore 29, which space 33 will permit the movement of the die on the spindle under the action of the hammer and the reaction of the spring 21. The hammer action will also cause movement of the floating hammer head cap 56 in an amount permitted by the space provided by the recess 54.

'Ihe operation of the hammer itself is as follows: In the normal position as shown in Fig. 2, the chamber 48 will be provided in the lower portion of the bore 4|, and when valve 40 is opene-d the compressed air will enter chamber 48 and cause the hammer 44 to be raised at a comparatively slow rate. The hammer will continue to be raised and outlet ports 5I will be closed since they will then be within the reduced portion 42 of the cylinder bore, and when inlet ports 50 and 52 become exposed to the air pressure in the chamber 48 the air will be passed into the central bore 41 and into the upper chamber 49, whereupon the hammer will be forced downwardly with a sharp blow until the exhaust ports 5| pass out of the bore 42 and release the pressure of chamber 49 and bore 41 to the outside air through the space formed by the aprons 43. Thereupon chamber 48 will again be closed and the air pressure again cause the hammer to be raised and lowered, as will be understood by those skilled in the art. It will be apparent that the chamber 48 is of such dimensions that the enlarged portion 45 of the hammer will strike against the upper surface formed by the reduced cylinder bore 42 and still permit of a space being left in the semi-circular recesses 54 so that the action of the hammer will not cause the hammer head 56 to be fractured under the action of the hammer 44. When the Work is placed on the die and under the hammer, the action of spring 21 will force the die 28, hammer head cap 56, and hammer 44 upwardly so that chamber 48 will be formed and permit the compressed air to enter and start the operation of the hammer. As hereinbefore stated, the manual vertical adjustment of the device with re-lation to the work will vary the magnitude of the blows delivered by the hammer; and this adjustment is compensated for by the free vertical movement allowed to the hammer head cap and the upward thrust of the anvil by the spring 21, thereby holding the work between' the hammer cap and the anvil irrespective of the relative position of the device as a whole with the work.

` Figure 8 further shows the adjustable position of the spindle 'VI to permit it to be moved into and out of position for work. The frame member I8 has a pair of adjacent reduced portions 8| meeting in a hinged or pivoted joint 82 and a locking sleeve 83 is provided having a reduced bore 84 slightly larger than portions 8| and an enlarged bore 85. A collar 8E is secured to frame member I8 by a pin 81 and a spring 88 is located in bore 85. By this arrangement sleeve 83 can vbe pulled back against the action oi the spring thus permitting the pivoted joint to be broken and the spindle T1 swung out of position and vice versa.

As has already been stated, the frame member I8 is substantially rigid and the formation of the die holding means is such that a perfect alignment can be preserve-d between the die holder, die, and the hammer, which is of particular importance when the work to be hammered is flat and a perfect, at surface is to be formed on the work.

It will be further obvious from the foregoing description that my invention accomplishes the results as stated in the objects, and that an efficient and `simplied construction has been achieved.

It will be understood that the foregoing description is illustrative only and that changes and modications may be made without departing from the scope of the invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A pneumatic tool comprising in combination a substantially rigid U-shaped frame member, a hammer cylinder mounted on one end of said frame member and having a hammer and a vertically free moving hammer head cap mounted on said hammer cylinder, means for limiting the upward movement of said cap at a point below the upper end of the throw of the hammer, a die holder and die mounted on the other end of said frame member, and resilient means forcing said .die holder an-d die toward said hammer head cap, the arrangement being such that the movement of the die and die holder toward the hammer head cap clue to said resilient means is limited by said cap at the upper limit of movement of the same.

2. A pneumatic tool comprising in combination a substantially rigid U-shaped frame member, a hammer cylinder mounted on one end of said frame member and having a hammer and a vertically free moving hammer head cap detachably mounted on said hammer cylinder, means for limiting the upward movement of said cap at a point below the upper end of the throw of the hammer, a die holder mounted on the other end of said frame member, and a removable die on said die holder, and resilient means forcing said die holder and die toward said hammer head cap, the arrangement being such that the movement of the die and die holder toward the hammer head cap due to said resilient means is limited by said cap at the upper limit of movement of the same.

3. VA pneumatic tool comprising a substantially U-shaped frame member, a hammer cylinder mounted thereon, a pneumatic hammer in said cylinder, a hammer head cap oscillatably mounted in sai-d hammer cylinder and vertically movable thereon, means for limiting the upward movement of said cap below the upper end of the throw of the hammer, a die holder, one of a number of interchangeable dies on said die holder, and means for yieldingly forcing said die and die helder toward said hammer head, the arrangement being such that the movement of the die and die holder toward the hammer head cap due to said resilient means is limited by the hammer head cap at the upper limit of movement of the same.

4. An impact tool comprising a housing, a piston hammer reciprocable therein, means for reciprocating said hammer, a substantially rigid bowed member fixedly attached at one end to said housing, an anvil support pivoted at the free end of said bowed member, an anvil yieldably carried by said support, and means for retaining said support in position to present said anvil in cooperative relation to said hammer.

5. An impact tool comprising a housing, a hammer reciprocable therein, a bowed support Xedly attached at one end to said housing, an anvil support pivotally mounted on the free end of said support, an anvil carried by said anvil support, a spring for yieldingly urging said anvil into cooperative relation with said hammer, and means for locking said anvil support in operative position.

6. An impact tool comprising a housing, a piston hammer reciprocable therein, means for reciprocating said hammer, a substantially rigid bowed member xedly attached at one end to said housing, an anvil support pivoted at the free end of said bowed member, an anvil yieldably carried by said support, and means for retaining said support in position to present said anvil in cooperative relation to said hammer, said support retaining means including a locking pin adapted to engage sai-d pivoted anvil support.

'7. An impact tool comprising a housing, a piston hammer reciprocable therein, means for reciprocating said hammer, a substantially rigid bowed member xedly attached at one end to said housing, an anvil support pivoted at the free end of said bowed member, an anvil yieldably carried by said support, and means for retaining said support in position to present said anvil in cooperative relation to said hammer, said means comprising a sleeve member engaging the adjacent portions of the pivoted anvil support and the bowed member.

8. An impact tool comprising a housing, a piston hammer reciprocable therein, means for reciprocating said hammer, a substantially rigid bowed member xedly attached at one end to said housing, an anvil support pivoted at the free en-d of said bowed member, an anvil yieldably carried by said support, and means for retaining said support in position to present said anvil in cooperative relation to said hammer, said means comprising a retractible sleeve member .engaging the adjacent portions of the pivoted anvil support and the bowed member.

9. A pneumatic tool comprising in combination a substantially rigid U-shaped frame member, a hammer cylinder and hammer mounted on one end of said frame member, a spindle mounted on the opposite end of said frame and in alignment with said hammer, a shoulder at the base of said spindle, a cap mounted to reciprocate on said spindle, a spring interposed between said cap and said shoulder, means for limiting the outward movement of the cap, and a die having a bore to receive said spindle, and with its base resting on said cap, substantially as described,

10. A pneumatic tool comprising in combination a substantially rigid U-shaped frame member, a hammer cylinder and hammer mounted on one end of said frame member, a spindle mounted on the opposite end of said frame and in alignment with said hammer, a shoulder at the base of said spindle, a cap mounted to reciprocate on said spindle, a spring interposed between said cap and said shoulder, means for limiting the outward movement of the cap, and a die having a bore to receive said spindle, and with its base resting on said cap, and means on said die to facilitate turning the same on its longitudinal axis, substantially as described.

11. A pneumatic tool comprising in combination a substantially rigid U-shaped frame member, a hammer cylinder and hammer mounted on one end of said frame member, a spindle mounted on the opposite end of said frame and in alignment with said hammer, a shoulder at the base of said spindle, a cap mounted to reciprocate on said spindle, a spring interposed between said cap and said shoulder, means for limiting the outward movement of the cap, and a die having a bore to receive said spindle, and with its base resting on said cap, said spindle being pivotally mounted to the respective end of {the U-shaped frame, substantially as described.

12. A pneumatic tool comprising in combination a substantially U-shaped frame member, a hammer cylinder mounted on one end of said frame member, a hammer in said cylinder, a hammer head cap mounted 0n one end of said cylinder, said cylinder and cap having complementary groove and flange portions connecting the same and permitting a limited vertical movement of said cap to vary the relative positions of the hammer and cap to vary the effective hammer stroke, a die holder mounted on the other end of said frame member, and a removable die on said die holder, substantially as described.

13. A pneumatic tool comprising in combination a substantially rigid U-shaped frame member, a frame cylinder mounted on one end of said frame member, a hammer in said cylinder, a hammer head cap mounted on the end of said cylinder, said cylinder and cap having complementary groove and flange portions connecting the same and permitting a limited vertical movement of said cap to vary the relative positions of the hammer and cap to vary the effective stroke, and resilient means adapted to retain said groove and flange portions in operative position, a die holder mounted on the opposite end of said frame member from said cylinder, and a removable die on said die holder.

FERDINAND H. BORM. 

